The roll-on system has been known for decades.
A prototypical device is disclosed in U.S. Pat. No. 2,749,566.
Although dispensers similar to that represented in U.S. Pat. No. 2,749,566 have had widespread commercial acceptance, they present certain disadvantages of use. One of them lies in the relatively small size of the ball, which makes application of the content of the container difficult, especially when, as in this case, the product intended to be applied not only includes liquids, but also more viscous fluids, such as gels, creams, emulsions or sauces, amongst others, as well as fluids that may contain small solids such as seeds, as would be the case with grated tomatoes.
There are other dispensers with rolling spheres that incorporate a number of dividers between the sphere and the inner surface of the cap, which facilitates outlet of the product even when the latter has limited fluidity, as in the case of cosmetics and hygiene products.
This is the case of Spanish patent of invention ES452445, which relates to a sphere with a smooth surface housed in a cap whose inner wall shave a number of protrusions that support the sphere and act as dividers, thereby generating a passage way between the sphere and the walls of the cap, and favouring passage of the product.
Another proposed solution is reflected in patent ES2138062, which arises from European patent EP0712592, wherein the rolling sphere is pressed against the upper spout of the cap by elastic elements, such that the container is closed due to the complementary geometries, as said elastic elements that push the sphere against the spout of the cap may be easily brought down, thereby allowing for recoil of the sphere and, consequently, outlet of the product.
There are other solutions designed to favour the outlet of the product that use a cap with protrusions which may even configure a number of channels; in this regard, the following are worth mentioning:                ES260235U, related to a dispenser of the type that comprises a rolling sphere with a smooth surface housed in a cap, said cap comprising protrusions in its inner side that are suitable to maintain a certain distance between the sphere and the cap, thereby allowing for outlet of the product.        ES452445 relates to a dispenser of the type that comprises a rolling sphere with a smooth surface housed in a cap that presents protrusions in its inner side, in order to maintain the sphere away from the cap, thereby allowing for outlet of the carrier; in this case, the sphere presents a certain span between two retaining rings, such that it acts as a valve that opens and/or closes the product container.        EP1591035, relating to a dispenser of the type that comprises a rolling sphere housed in a cap and protrusions in the inner side of the cap; in this case, magnetic solutions are used to contribute to controlling the dispensing.        WO 2008/057482 claims a dispenser of the type that comprises a rolling sphere with a smooth surface housed in a cap that presents a plurality of channels in its inner side, in order to facilitate outlet of the product from the interior of the container, the outlet being favoured by a piston system incorporated in the container.        ES260235U relates to a dispenser of the type that comprises a rolling sphere housed in a cap, and this utility model proposes two alternative executions, since, in order to guarantee separation between the cap and the sphere, it envisages an execution example wherein the inner wall of the cap presents ribs that make up channels, with the sphere having a smooth surface, and a second, alternative execution, wherein the inner walls of the cap are smooth, but the surface of the sphere presents protrusions that act as dividers between the cap and the sphere, thereby allowing for passage of the product.        
None of the aforementioned patents or utility models propose a dispenser wherein the cap presents a number of grooves and, at the same time, the sphere presents a surface with treads which, in turn, may form channels; this is due to the fact that, when two surfaces, that of the sphere and that of the inner side of the cap, come in contact or create friction between them, if both of them have treads, they tend to engage with one another and, consequently, the device loses all its efficacy.
However, for the types of products intended to be dispensed, which comprise viscous fluids such as gels, creams, emulsions, sauces or even some crushed vegetables, such as tomatoes, that may have seeds, it is necessary to have joint operation of channels which allow for outlet of the product and a rolling sphere which, on the one hand, contributes to outlet of the product and, on the other hand, applies it on the target surface, for example, as in this case, the surface of a toast.
In order to apply the product, a certain tread is also necessary on the sphere, such that the sphere grips the surface of the target, which may be, for example, a slice of toasted bread, thereby generating sufficient friction to force pivoting of the sphere.